The present invention relates to an imaging and treatment head for imaging and treating organs or tissues of living beings, and usable in particular for treating various tumors, such as tumors of the thyroid, breast, or uterus. The present invention also relates to a method of manufacturing a component part of the head. The present invention consequently relates to the field of therapy devices, and more particularly to therapy devices for performing therapy with ultrasound monitoring, and more particularly to therapy devices using power ultrasound. Treatment using focused power ultrasound is known under the acronym HIFU (High Intensity Focused Ultrasound).
The treatment and imaging head of the invention is for mounting on an arm provided with motors, so as to be able to displace the head accurately in various directions. The head is also connected to an electronic control and treatment cabinet, and to a scanner, e.g. an ultrasonic scanner. In addition, the head is generally connected to a cooling unit that causes a refrigerated propagation medium to circulate inside the head. This is a relatively conventional design for an ultrasonic treatment and imaging head using HIFU treatment and an ultrasonic imaging probe, for example. This is only one particular type of treatment device: naturally, other types of treatment device exist that use other imaging and treatment techniques, but without going beyond the ambit of the invention.
The treatment performed by the treatment means of the head may use optionally-focused ultrasound. Amongst treatments using focused ultrasound, treatment using HIFU is already known. The invention preferably, but not exclusively, uses that type of HIFU treatment. Other types of treatment can be used in the ambit of the present invention, and in particular any treatment using waves or radiation that is likely to reach a target that is situated in an organ or a tissue of a living being. The treatment of the present invention is preferably non-invasive: however, invasive treatment can also be envisaged in the ambit of the present invention.
In addition to its treatment means, the imaging and treatment head also includes imaging means that may be of any kind, such as imaging using an ultrasonic probe, an X-ray probe, or IRM, for example. However, imaging using ultrasound is preferred in the ambit of the present invention.
There already exist such imaging and treatment heads that make it possible, in a single unit, to combine the treatment means and the imaging means necessary for locating and showing the target for treatment. It is essential to locate the target for treatment properly, so as to avoid damaging healthy portions of the tissue or of the organ for treatment. To do this, the imaging means must deliver a reliable and accurate representation of the site of the target.
To enable the target for treatment to be located accurately, it is essential for the treatment means and the imaging means to be mutually positioned relative to each other in completely accurate manner. Initially, it is possible to put the imaging means into place, so that they can take an accurate image of the site for treatment. The imaging means may then be moved away and the treatment means are then put into place and positioned very accurately in order to correspond with the image taken by the imaging means. Another technique is to couple the imaging means and the treatment means mechanically on a single head at precise locations.
The imaging means, e.g. an ultrasonic probe, are mounted on the head in an appropriate housing or fastened into place by adhesive. The imaging means are thus integrated in the head. With such a head, the type of imaging means is determined by the head, given that the imaging means are bonded to the head or are installed in a housing specifically for said means. It is therefore not possible to use other imaging means that would perhaps be more appropriate for some particular use or for some particular site for treatment. For example, depending on the organs for treatment, it can be preferable to use ultrasonic probe having a linear or a curved array, or operating in a determined range of frequencies.
An object of the present invention is to overcome the above-mentioned prior-art drawbacks by defining an imaging and treatment head that can be more modular, but without neglecting the accurate positioning of the imaging means relative to the treatment means.
To achieve this object, the present invention proposes that the imaging means are mounted in removable manner on an adapter that ensures positioning of the imaging means relative to the treatment means. Advantageously, the head includes a mounting body including a fastener zone for fastening the treatment means, and a mounting housing for mounting the imaging means, said mounting housing receiving said adapter in which the imaging means are mounted in removable manner. It is therefore the adapter that makes it possible to position the imaging means accurately relative to the mounting body of the head. The adapter thus constitutes an intermediate or transition part that takes into account firstly the shape of the mounting housing of the body, and secondly the shape of the imaging means. The adapter thus makes it possible to couple the imaging means accurately to the head, on which the treatment means are also mounted. However, the adapter enables the imaging means to be independent of the head with regard to the respective shapes of the imaging means and of the mounting housing, since it is the adapter that enables them to be connected together. In this sense, the adapter makes it possible to uncouple the imaging means from the head. Consequently, by using another type of adapter that matches another type of imaging means, it is possible to mount said other imaging means on the head of the invention in accurate and removable manner. Consequently, by providing a set of adapters that are compatible with a wide range of imaging means, it is possible to mount any imaging means on the head of the invention.
In an advantageous embodiment, the head includes a propagation space containing a propagation medium that is suitable for transmitting the waves or radiation emitted by the imaging means and/or the treatment means, the body forming a window that puts the housing into communication with the propagation space, said imaging means including a tip portion and a base portion, said tip portion incorporating an emitter/receiver face for emitting/receiving waves or radiation, and for being received in the adapter in such a manner as to emit through the window in the propagation space. The adapter preferably includes a front wall that is positioned in front of the emitter face of the imaging means and that closes the window at least in part, said front wall forming a diverging lens that is suitable for distancing the focal point of the waves or radiation emitted through the lens and the propagation space. The adapter is thus used to displace the focal point of the imaging means. This is particularly advantageous when an ultrasonic probe is used having a wave emitter/receiver face that is normally for coming into direct contact with the skin of the patient. However, in an imaging and treatment head, the emitter/receiver face of the ultrasonic probe is not in contact with the skin of the patent, but is offset by a distance of about 3 centimeters (cm). This is why it is necessary to distance the focal point of the waves emitted by the ultrasonic probe by a distance of about 3 cm. In the present invention, the adapter is used to form the diverging lens that makes it possible to offset the focal point of the ultrasonic probe by a distance of about a few centimeters, preferably 3 cm. Between the emitter/receiver face of the probe and the skin of the patient, the waves propagate through the propagation space that is filled with a propagation medium that is conventionally water.
According to another advantageous characteristic of the invention, the adapter includes a sealing ring that ensures sealing between the imaging means and the mounting housing, the imaging means advantageously deforming the ring while they are being inserted into the ring. Thus, in addition to its function of positioning the treatment means, the adapter also provides a sealing function that is advantageously improved by the ring deforming in such a manner as to create intimate contact between the ring and the mounting housing and between the ring and the imaging means. The adapter thus performs a role of a sealing gasket. The adapter is advantageously made of elastomer material.
The sealing ring may be combined with the optionally-diverging lens. The emitter/receiver face of the imaging means is then in direct contact with the propagation medium of the propagation space.
According to another characteristic of the invention, the imaging means are held in position in said adapter by means of a holding system that is suitable for urging the imaging means into said adapter. The holding system thus presses the imaging means against the adapter that is thus wedged between the imaging means and the mounting housing of the body. The holding system thus makes it possible to block the imaging means in the adapter, thereby providing accurate positioning of the emitter/receiver face of the imaging means relative to the treatment means. In addition, the thrust force created by the holding system improves the sealing at the adapter.
In an advantageous embodiment, the imaging means comprise an ultrasonic probe having a linear array. The body preferably forms an elongate window, the linear array being positioned so as to emit through the window, the treatment means being positioned on either side of the elongate window. The use of a linear-array ultrasonic probe disposed in a mid-plane, dividing the treatment means into two substantially identical portions, is a characteristic that may be protected independently of the fact that the imaging means are mounted in removable manner on an adapter. In other words, this characteristic may be protected independently.
In addition, the treatment means may comprise a focused piezoelectric transducer of the HIFU type. Thus, both the imaging means and the treatment means use ultrasonic, such that the propagation space may be filled with a propagation medium that is appropriate both for the imaging means and for the treatment means.
The invention also provides a method of manufacturing an adapter for imaging means incorporated in a focused-imaging/treatment head according to any preceding claim, in which said method comprises the steps of:
a) providing imaging means that include a tip portion that includes an emitter face through which waves or radiation are transmitted;
b) digitally scanning said tip portion of the imaging means in order to obtain a geometrical representation and an accurate estimation of the dimensions of said tip portion;
c) providing a mold that presents a shape and dimensions that match the result obtained in step b); and
d) pouring one or more elastomeric materials into the mold so as to obtain a molded product that forms an adapter that is suitable for being positioned accurately on the tip portion of the imaging means.
Advantageously, the mold is made with dimensions that are slightly smaller than the tip portion, such that the adapter is naturally compressed while the imaging means are inserted in the head.